Angle of projection of a projectile is changed, keeping initial velocity constant. Find the rate of change of maximum height. Range of the projectile is $\mathrm{R}$.
(A) $(\mathrm{R} / 4)$
(B) $(\mathrm{R} / 3)$
(C) $(\mathrm{R} / 2)$
(D) $\mathrm{R}$